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If you can't get the chain rail guide pin out with the slide hammer, you can use a puller/extractor like this one http://www.ebay.com/itm/Mercedes-Engine-Timing-Chain-Guide-Rail-Pin-Puller-Remover-Extractor-Tool-NEW-/281695829802?hash=item4196613f2a:g:Wn8AAOSwJSJXGDt6&item=281695829802&vxp=mtr This tool should remove stubborn guide rail pins.
As far as the vacuum line goes, if its just plastic line that is cracked, it is possible to just insert a rubber vacuum hose piece inbetween the broken plastic sections. If the rubber is cracked, just use bulk rubber hose.
By carb, I think you mean the throttle motor. That large plastic line is the brake booster vacuum line which you won't be able to get in bulk. You will have to buy that line separate. Is this what you are talking about? http://www.ebay.com/itm/2004-Mercedes-SLK230-R170-2-3L-Kompressor-Power-Brake-Booster-Vacuum-Line-Tube-/262638311187?fits=Make%3AMercedes-Benz%7CModel%3ASLK230&hash=item3d26769713:g:b6QAAOSwYIxX5I3W&vxp=mtr
You're welcome! Good luck!